Western · tropical zodiac

Twelve signs, and when each thing was first said

Of 204 character claims traceable across this corpus, 23 are attested both in antiquity and today. 75 reach us from the Edwardian popularisers with nothing older behind them, and 53 have no source at all before 1929. A further 53 were said by the tradition and then dropped.

None of that makes the tradition less interesting. It makes the usual sales pitch — the ancients knew — checkable, which nobody else in this niche lets you do.

The twelve

Dates are computed for 2025 from the Sun’s true longitude, not taken from a table. They are not the same every year — see below.

Why our dates disagree with everyone else’s

A sign begins the instant the Sun reaches a particular ecliptic longitude. That instant moves by roughly six hours a year across the leap-year cycle, and drifts across decades, so a fixed table is wrong for anyone born near a boundary.

The Sun entered Aries at 15:28 UTC on 20 March 1989 and at 03:06 UTC on 20 March 2024. Someone born at noon on the first date is a Pisces. Someone born at noon on the second is an Aries. Every site that prints a fixed range gets one of them wrong.

How far each boundary moved between 1925 and 2025, in UTC.
sign	earliest start	latest start	spread
Aries	20 March	21 March	35.9 h
Taurus	19 April	21 April	36.5 h
Gemini	20 May	22 May	37.1 h
Cancer	20 June	22 June	37.5 h
Leo	22 July	23 July	37.5 h
Virgo	22 August	24 August	37.2 h
Libra	22 September	24 September	36.6 h
Scorpio	22 October	24 October	35.9 h
Sagittarius	21 November	23 November	35.3 h
Capricorn	21 December	22 December	35.0 h
Aquarius	19 January	21 January	34.9 h
Pisces	18 February	19 February	35.2 h

Every boundary spans more than a day. None of them can be tabled honestly.

What is in the corpus

153 claims backed by three or more independent voices, 51 attributed to a named classical writer, 448 correspondence values and 51 recorded disputes, read from seven classical and early-modern texts and a panel of contemporary publishers.